axismd.ai
FANUC Controller
Program/G-code · Intermediate · 10-20 minutes
Fanuc Alarm PS023 - Wrong Arc Direction
Fanuc PS023 occurs when the programmed arc direction (G02/G03) conflicts with the geometric relationship between start point, end point, and arc center (I, J, K values). The CNC calculates that the specified clockwise or counterclockwise direction cannot produce a valid circular path with the given coordinates, often due to programming errors in arc endpoint definition or incorrect I/J/K offsets.
PS023
Fanuc Alarm PS023 - Wrong Arc Direction
Circular Direction Error
The arc direction (CW/CCW) results in an invalid path. The commanded arc cannot be executed as specified.
Root Cause Summary
Fanuc PS023 occurs when the programmed arc direction (G02/G03) conflicts with the geometric relationship between start point, end point, and arc center (I, J, K values). The CNC calculates that the specified clockwise or counterclockwise direction cannot produce a valid circular path with the given coordinates, often due to programming errors in arc endpoint definition or incorrect I/J/K offsets.
Safety
- Verify arc path before running
Causes and Fixes
- 1
Identify the exact block number causing PS023 from the alarm screen (ALARM > HISTORY shows program path and line number). Note the G02 or G03 command and all coordinate values.
- 2
Verify the arc definition: Check if I/J/K values (incremental distance from arc start to center) create the intended arc radius. Calculate distance from start to center and end to center - they must be equal within tolerance set by parameter 5410 (Arc Radius Tolerance, typically 0.5mm default).
- 3
Swap G02 to G03 or G03 to G02 in the problem block and re-execute. Verify the arc direction matches the intended tool path using graphical verification on the CNC (EDIT > PROGRAM > [SELECT] > GRAPH display).
- 4
If using CAM-generated code, verify post-processor arc output settings. Check parameter 1004 bit 2 (ARC) to confirm arc command support is enabled. Review G17/G18/G19 plane selection before arc block to ensure correct plane is active.
Seeing Multiple Alarms?
Seeing another alarm with this one? Enter the code.
Get machine-aware diagnosis
AxisMD logs alarms against your actual machines, tracks patterns, and gives AI context your manual doesn't have.
Start freeWas this guide helpful?
Always verify with your machine manual or a certified technician before performing service procedures.